Create Your First Tizen Wearable Native Watch Application

A wearable native watch application is created using the C language, and can be run on Tizen wearable devices to display a customized watch face to the user.

Study the following instructions to help familiarize yourself with the Tizen native application development process as well as using the Tizen Studio and installing the created application on the emulator or target device. With the instructions, you can create and run a basic wearable native watch application, which displays some text and the current time on the screen:

Before you get started with developing Tizen applications, download and install the Tizen Studio.

Creating a Project

The following example shows you how to create and configure a basic wearable native watch application project in the Tizen Studio. An application project contains all the files that make up an application.

The following figure illustrates the application to be created. The application screen displays the Hello Watch text and the current time, which continues to be refreshed every second while the application runs.

Figure: Wearable native Watch application

To create the application project:

Launch the Tizen Studio.

In the Tizen Studio menu, select File > New > Tizen Project.

The Project Wizard opens.

In the Project Wizard, define the project details.

The Project Wizard is used to create the basic application skeleton with the required folder structure and mandatory files. You can easily create different applications by selecting an applicable template or sample for the Project Wizard to use.

Select the Template project type and click Next.

Select the profile (Wearable) and version from a drop-down list and click Next.

The version depends on the platform version you have installed and with which you are developing the application.

Select the Native Application application type and click Next.

Select the Watch template and click Next.

Define the project properties and click Finish.

You can enter the project name (3-50 characters) and the unique package ID. You can also select the location and working sets by clicking More properties.

The Project Wizard sets up the project, creates the application files using the default content from the template, and closes. For more information on the Project Wizard and the available templates, see Creating Tizen Projects with Tizen Project Wizard.

You can see the created project in the Project Explorer view. The most important files and folders include:

inc: Default folder for included source files

res: Folder for resource files used by the application only

shared: Folder for resource files to be shared with other applications

src: Folder for source code files

lib: Folder for external library files

tizen-manifest.xml: Manifest file used by the platform to install and launch the application

Advanced: Define advanced features, such as application metadata and some miscellaneous options.

Source: View and edit the source code of the tizen-manifest.xml file. Changes made and saved on the other tabs are reflected in the source code and vice versa.

Note :

The tizen-manifest.xml file must conform to both the XML file format and the Tizen native application specification requirements. Editing the file in the Source tab is intended for advanced users only.

Understanding the Source Code

Pay attention to the following main issues in the application source code (in the inc/watch.h and src/watch.c files), to understand how the application is designed and how it works. For source code details related to the UI, see Designing a Simple UI.

The watch application is initialized to use the functions and data types of the Watch Application API by including the <watch_app.h> header file in your application:

#include <watch_app.h>

All header files that you need are already included in the watch.h file, which is generated by the Tizen Studio when the template project is created.

The life-cycle callbacks manage specific parts of the application life-cycle. They are set in the watch_app_lifecycle_callback_s structure, and the structure is passed to the watch_app_main() function of the Watch Application API to start the watch application event loop:

For more information on the application life-cycle callbacks, see Applications.

An ambient mode is available on a low-powered wearable device. In this mode, the watch application shows a limited UI and receives only the ambient tick event every minute to reduce power consumption.

The details of the limited UI drawn in the ambient mode depend on the device. In addition, due to the ambient mode being a low power mode, there are limits to the colors that can be shown on the screen. Usually, when designing the ambient mode UI, draw it with limited colors (cyan, magenta, yellow, red, green, blue, black and white), and use less than 15% of the pixels on the screen. If you do not want to draw your own ambient mode UI, set the ambient-support attribute to false in the watch application manifest file to allow the platform to show a default ambient mode UI.

Note :

To use the ambient mode, the user must enable it in the device settings. In addition, on the Gear S2 device, the ambient mode activates only when you are wearing the watch on the wrist.

The ambient_tick callback is triggered every minute while the device is in the ambient mode. You can use the callback to update the time on your watch application in the ambient mode. In this callback, do not perform time-consuming tasks and always update the UI as quickly as possible. The platform can put the device to sleep shortly after the ambient tick expires.

Building Your Application

After you have created the application project, you can implement the required features. In this example, only the default features from the project template are used, and no code changes are required.

When your application code is ready, you must build the application. The building process performs a validation check and compiles your files.

You can build the application in the following ways:

Automatically

The automatic build means that the Tizen Studio automatically rebuilds the application whenever you change a source or resource file and save the application project.

To use the automatic build:

Select the project in the Project Explorer view.

In the Tizen Studio menu, select Project > Build Automatically.

A check mark appears next to the menu option.

You can toggle the automatic build on and off by reselecting Project > Build Automatically.

Manually

The manual build means that you determine yourself when the application is built.

To manually build the application, right-click the project in the Project Explorer view and select Build Project.

Figure: Manually building the application

Alternatively, you can also select the project in the Project Explorer view and do one of the following:

In the Tizen Studio menu, select Project > Build Project.

Press the F10 key.

You can have more than one build configuration. To see the current active configuration or change it, right-click the project in the Project Explorer view and select Build Configurations > Set Active. The default configuration is Debug. For more information, see Building Applications.

In the Project Explorer view, right-click the project and select Run As > Tizen Native Application.

Alternatively, you can also select the project in the Project Explorer view and do one of the following:

Press the Ctrl + F11 key.

Click the run icon in the toolbar.

If you have created multiple emulator instances, select the instance you want from the combo box in the toolbar before selecting to run the application. If you select an offline emulator, it is automatically launched when you select to run the application.

Confirm that the application launches on the emulator.

Note :

If the emulator display has switched off, you cannot see the application launch. To switch the display on, click the Power key (in the lower-right corner of the emulator).

Change the watch face.

To change the watch face and make the installed watch application visible:

If the emulator display has been switched off, activate it by pressing the Power key (in the lower-right corner of the emulator).

On the home screen (showing the default watch face), press the Power key.

Press the Back key (in the upper-right corner of the emulator device) multiple times, until the home screen with your new watch face is shown.

While the application is running, the Log view in the Tizen Studio shows the log, debug, and exception messages from the methods defined in the log macros. To see the view, in the Tizen Studio menu, go to Window > Show View > Log.

In the first attempt, the connection fails and the device asks for user confirmation. To allow Gear to read log data, copy files to and from your computer, and install the application manually, click the accept mark.

In the Device Manager, confirm that the device is connected (shown in the device list).

In Project Explorer view, right-click the project and select Run As > Tizen Native Application.

Alternatively, you can also select the project in the Project Explorer view and do one of the following:

Press the Ctrl + F11 key.

Click the run icon in the toolbar.

If you have both a connected device and existing emulator instances, select the device from the combo box in the toolbar before selecting to run the application.

Confirm that the application launches on the target device.

Like with the emulator, you can change the watch face in the device settings to see the watch application on the home screen.

Note :

The application is launched using the default debug run configuration. To create and use another configuration:

In the Project Explorer view, right-click the project and select Run As > Run Configurations.

In the Run Configurations window, click the New Launch Configuration icon (), define the configuration details, and launch the application by clicking Run.

Designing a Simple UI

The wearable watch application created with the Watch template has a simple user interface with a label component showing the Hello Watch text and the current time (hour, minute, and second). The UI is created using EFL.

In the ambient mode, the Watch template UI is identical to the normal UI, except that is shows the current time without the seconds.

Figure: User interface in the Watch template (ambient mode on the right)

Creating the Basic UI

The UI in the Watch template contains the following components:

The EFL UI always contains a window component, which is the root component of the entire UI.

The application uses the conformant component as a container for other UI components.

The label showing the Hello Watch text and the current time is implemented with a label component.

The UI is created in the watch.c file:

Data structure

A pointer to the UI components is stored in the appdata_s data structure:

The conformant component is used as a container for the other UI components:

The component is the first object added inside the window with the elm_conformant_add() function.

The conformant component is set as a resize object of the window by using the elm_win_resize_object_add() function. It means that the conformant size and position are controlled by the window component directly.

The watch_time_get_current_time() function retrieves the current time, and the update_watch() function uses the current time to set the label component content. Finally, the watch_time_h handle is deleted.

In the update_watch() function, the watch_time_h handle is used to retrieve the current time elements (hour, minute, and second) with the watch_time_get_hour24(), watch_time_get_minute(), and watch_time_get_second() functions of the Watch Application API.

The text for the label component is defined (based on whether the normal or ambient mode is used), and set with the elm_object_text_set() function.